Split ExtensionMessageFilter up into a UI thread part and an IO thread part.

extensions/browser/io_thread_extension_message_filter.cc

Index: extensions/browser/io_thread_extension_message_filter.cc
diff --git a/extensions/browser/io_thread_extension_message_filter.cc b/extensions/browser/io_thread_extension_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8b0188b6cd282c3a345c50daf90a95c38a1f83bb
--- /dev/null
+++ b/extensions/browser/io_thread_extension_message_filter.cc
@@ -0,0 +1,75 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extensions/browser/io_thread_extension_message_filter.h"
+
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/resource_dispatcher_host.h"
+#include "extensions/browser/extension_function_dispatcher.h"
+#include "extensions/browser/extension_system.h"
+#include "extensions/browser/info_map.h"
+#include "extensions/common/extension_messages.h"
+#include "ipc/ipc_message_macros.h"
+
+using content::BrowserThread;
+
+namespace extensions {
+
+IOThreadExtensionMessageFilter::IOThreadExtensionMessageFilter(
+    int render_process_id,
+    content::BrowserContext* context)
+    : BrowserMessageFilter(ExtensionMsgStart),
+      render_process_id_(render_process_id),
+      browser_context_id_(context),
+      extension_info_map_(ExtensionSystem::Get(context)->info_map()),
+      weak_ptr_factory_(this) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
+
+IOThreadExtensionMessageFilter::~IOThreadExtensionMessageFilter() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+}
+
+void IOThreadExtensionMessageFilter::OnDestruct() const {
+  // Destroy the filter on the IO thread since that's where its weak pointers
+  // are being used.
+  BrowserThread::DeleteOnIOThread::Destruct(this);
+}
+
+bool IOThreadExtensionMessageFilter::OnMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(IOThreadExtensionMessageFilter, message)
+  IPC_MESSAGE_HANDLER(ExtensionHostMsg_GenerateUniqueID,
+                      OnExtensionGenerateUniqueID)
+  IPC_MESSAGE_HANDLER(ExtensionHostMsg_ResumeRequests,
+                      OnExtensionResumeRequests);
+  IPC_MESSAGE_HANDLER(ExtensionHostMsg_RequestForIOThread,
+                      OnExtensionRequestForIOThread)
+  IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void IOThreadExtensionMessageFilter::OnExtensionGenerateUniqueID(
+    int* unique_id) {
+  static int next_unique_id = 0;
+  *unique_id = ++next_unique_id;
+}
+
+void IOThreadExtensionMessageFilter::OnExtensionResumeRequests(int route_id) {
+  content::ResourceDispatcherHost::Get()->ResumeBlockedRequestsForRoute(
+      render_process_id_, route_id);
+}
+
+void IOThreadExtensionMessageFilter::OnExtensionRequestForIOThread(
+    int routing_id,
+    const ExtensionHostMsg_Request_Params& params) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ExtensionFunctionDispatcher::DispatchOnIOThread(
+      extension_info_map_.get(), browser_context_id_, render_process_id_,
+      weak_ptr_factory_.GetWeakPtr(), routing_id, params);
+}
+
+}  // namespace extensions